Feeding mechanism for rock drills



A. F'EUCHT June 11, 1940.

2 Sheets-Sheet 1 Filed March 17, 1938 ALBERT F'l/CHT INVENTOR W.. nh g MR4 pub Ln X X um vb vb pm VA pn vb uh pm vm VA VA ATTORNEY June 11, 1940.-

A. FEUCHT FEEDING MECHANISM FOR ROCK DRILLS 2 Sheets-Shet 2 Filed larch 17, 1938 ALBERT fZ'UCl/T INVENTOR ATTORNEY Patented June 11, 1940 UNITED STATES PATENT OFFICE 2,203,953 FEEDINGMECHANISM FOR ROCK mums Albert Feucht, Garfield Heights, Ohio, assignor to The Cleveland Rock Drill Company, Cleveland, hio, acorporation of Ohio Application March 17, 1938, Serial No. 196,438

Claims. (01. 121-9) This invention relates broadly to rockdrills, but more particularly to a power actuated reversible feeding mechanism for rock drills of the drill would cause it to drop to the lowerend of the support, resulting in serious inconveniences and often in personal injuries. To overcome this serious diificulty and prevent accidents arising ..therefrom, some automatic feeds were equipped with a brake mechanism which proved to be impractical because the operator couldnot possibly operate the brake fast enough to check the drop of the rock drill. l

In another effort to overcome this difficulty,

some of the automatic feeds were equipped with a screw carried by the support and engaged by. a nut carried by the rock drill and rotated by a suitable feeding motor. In order to move the ,drilling motor to and from the work at a rate r of speed which would justify the use of automatic feed, it was necessary for the screw threads to be of a relatively steep angle, which if self locking, would soon wearto such an extent as to allow the drop ofthe rock drill relative to the support. This construction also proved to be inefficient for checking the recoils ofthe drilling motor relative to its support. Due to the necessary clearance between the operative threads of the screw and nut, the jars of the rock drill resulting from the reversal of its piston strokes, were transmitted to the nut, thereby accelerating. the normal wear of the screw threads and often resulting in a premature deterioration of the entire mechanism. Another disadvantage of this screw and nut construction, resulted from its lime itation in the range of feed. Since the screw had to be at least as long as the feedingrange, it was found that a long. screw was not only difficult and expensive to manufacture, but that after assembly, thescrew being supported only actuated feeding mecha- It is therefore one object of this invention to produce a power actuated feeding mechanism for rock drills constructed in a manner preventing the rock drill to drop relative to its support when positioned for vertical drilling or drilling at an angle greater than the friction angle.

Another object of this invention is toproduce a feeding mechanism for rock drills including a flexible connection between the drill and its support, thereby reducing the wear of the operating parts of the feeding mechanism as well as the operating cost of the drill assembly.

Another object of this invention is to provide a rock drill with a power actuated feeding mechanism operable independently of the rock drill, and equipped with a device for selectively controlling its feeding speed.

Another object of this invention is to produce a feeding mechanism forming a compact and light assembly, which is strong, durable, efflcient and comparatively inexpensive to manufacture.

Other objects and advantages more or less ancillary to the foregoing reside in the specific construction and aggroupment of the elements peculiar to this structure, as will become apparent from a complete examination of this specification.

In the drawings: Fig. 1 is a sideelevational view of a rock drill embodying the invention with its support shown partly in section to illustrate details'of construction.

Fig. 2 is a longitudinal sectional view taken in a plane indicated by line 2-2 in Fig. 1.

Fig. 3 is an end elevational view of the assembly looking in the direction of the arrows 3-3 in Fi 1.

Fig. 4 is an enlarged longitudinal sectional view taken in a plane indicated by line 44 in Fig. 3.

Figs. 5 and 6: areviews similar to Fig. 4 but taken in planes indicated by lines5-,5 and 6-6 respectively in Fig. 3. p

Fig. '7 is an enlarged cross sectional view taken in a plane indicated by line 'l--'l in Fig. 3.

Fig. 8 is a cross sectional view taken in a plane indicated by line 88 in Fig. 5.

Fig. 9 is apartial cross sectional View taken in a plane indicated by line 99 in Fig. 6.

Fig. 10 is a cross sectional view taken in a plane indicated by line l0l0 in Fig. 5.

Figs. 11,. 12, 13 and 14 are partial cross sectional views taken in planes indicated by lines in Fig. 6.-

Fig. 15 is a longitudinal sectional view taken in a plane indicated by line I5I 5 in Fig. 5.

Fig. 16 is a longitudinal sectional view taken in a plane indicated by line Iii-I5 in Fig. 5.

Referring to the drawings in which like symbols designate corresponding parts throughout the several views, 29 represents a fluid actuated rock drill of. the drifter type having a piston (not shown) reciprocable therein for delivering impacts to a drill steel 2| slidably'mounted within a front housing 22. The rock drill 29, hereinafter referred to as the drilling motor, is provided with the usual guides 23 .slidable within correspending guideways 24 which extend substantially the full length of a shell or support 25. This support is preferably U-shap'ed in cross-section with one guideway 24 formed on each inner side wall thereof, and terminated toward the left in Fig. 1, hereinafter denoted as the rear end of,, Within the 28. Extending through this bracket near one side wall of the support 25, there is a bolt 29 carrying a relatively heavy compression spring 39 interposed between the head of the bolt and the bracket, while the threaded end of the bolt carries a special nut 3| having secured thereto by a cross pin 32 one end of a chain 33. The other end of this chain is affixed to the other side wall of the support 25 near the rear end thereof or to the handle 26 which is shown machined to receive a bolt 34 to which the rear end of the chain is aflixed by a pin'35.

Secured to the rear end of the drilling motor 29 by two long bolts 36, one on each side of the motor, there is the feeding mechanism including two housings 37 and 38L Secured to one side of the casing 31, there is a motive fluid connection 39 through which motive fluid may be admitted to a throttle valve 49 having a handle 4| located on the other side of the casing 31. From this throttle valve, motive fluid may be admitted into the drilling motor 29 for actuating the same through a throttle valve port 42, a passage 43, an annular chamber 44 and ports 45.

The casing 31 is provided with a vertical'bore 46 closed at its lower end by a plate 41 secured to the casing by bolts 48. The upper end portion of this bore is enlarged in a piston chamber 49 closed by a removable plug 59. Reciprocable within the chamber 49, there is a piston 5| having an integral stem 52 rec'iprocable within the bore 46, which stem has a passage 53 opening through the end thereof and capable of communication with the piston chamber 49 through a radial port 54.

The casing 38 is formed with a longitudinally ing areas 59 and 69 and two holding areas BI and 62, the area BI having motive fluid convey able thereto from the groove 51 through a passage 63, while the area 62 may be supplied with motive fluid from the groove 58 through a passage 64. Within the valve chamber 55, there are five annular grooves 65, 69, 91, 68 and 69. The two extreme grooves 65 and 99 open into a com-' mon exhaust passage 19, (Fig. 7) which leads to the atmosphere through an exhaust port II (Fig. 5), as will be explained later. The annular groove 66 is in communication with the upperend of the piston chamber 49 through a passage 12, while the groove 68 is in communication with the lower end of this chamber through a passage I3. From the piston chamber 49, the motive fluid may be admitted to the valve actuating area 69 via a small passage I4, and to the other actuating area 59 via a similar passage l5. Each actuating area 59 and 99 is in constant communication with the atmosphere through a .vent I9 of smaller cross sectional area than the passages 14 and I5.

Beside the fluid actuated valve 17, there is a feed regulating valve I8 rotatable within the easing 38 having an integral handle I9 which extends through a retaining nut 89, and held against accidental rotation by a spring pressed plunger I9 acting within corresponding notches I9 formed on the valve I8. This valve is provided witha central bore 8I leading to some operating parts ofthe mechanism through a passage 82 which is interconnected with the passage 19 through a groove 83 (Fig. 8). On its periphery, the valve I8 is formed with a longitudinal groove 84 capable of communication through a partly annular groove 84' (Fig.9) with an inlet passage 85 (Fig. 6) which opens into the casing 37 between the throttle valve 49 and the connection 39, and through which motive fluid is supplied to the feed regulating valve I8 independently of the throttle valve 49. On its periphery, the valve 18 is provided with five partly circular grooves 89, 81, 99, 89 and 99. The groove 89 is connected with the central bore 8| through a port 9 I ,while the groove 87 which is located within the same transversal plane as the groove 86, opens into the longitudinal slot 94 (Fig. 11). As shown in Fig. 12; the grooves 88 and 99 are also located within the same transversal plane with the groove 99 opening into the longitudinal groove 94, and the groove 89 connected with the central core 8i through a port 92. The groove 99 extends across the longitudinal groove 84, and is capable of communication with a port 93 which opens into the I annular groove 67 of the valve chamber 55.

Located within the casings 31 and 38 in coaxial relation with the center axis of the drilling motor 29, there is a rotatable stem 94 having its rear end rotatable within a bushing 95 held in position by a retaining plug 99, which plug also retains the usual cleansing fluid conveying tube 91 extending through the stem 94. The front end portion of the stem is journalecl within the casing 3'! and is formed with gear teeth 98 meshing with corresponding teeth. 99 cut onthe stem 52 of the piston. 5!, which teeth constitute the rack and pinion assembly shown in Fig. 15. termediate its ends, the stem 94 is formed with an enlargement I99 having pivotally mounted therein two sets of pawls IIlI and I92. In practice, each set includes three or four pawls, but

for the purpose of illustration only two pawls are shown, each pawl being urged by a spring pressed plunger I93 in operative engagement with the internal teeth IM-of a ring I95 which surrounds the enlargement I99 of the stem 94, and forms an integral part of a gear I96 rotatable on. the stem 94. Through the ring I95, there is a port 19' leading from the gear I96 inside of the ring, through which port fluid from the exhaust passage 19 is free to How into the ring I95 and therefrom to the atmosphere via the exhaust port II. The ring I95 is j ournaled within a hardened bushing I91 having slidable therein a reciprocable wedge in the form of a sleeve I98 provided with an external annular flange I99 the side walls of which form opposed actuating areas I II! and III. The area IIII is capable of communication with either the groove 86 or 81 of the feed regulating valve I8 through a port IE2 (Fig; 11), while the area I II is capable of communication with either the groove 88 or not that valve through a port II3 (Fig. 12). Internally, the

sleeve I08 is formed with a substantially V-shaped annular bead H4 engageable with one end portion of the pawls IM and I132 whichIprotrudes from the ring I05. As shown in Fig. 5, the aforesaid end of the pawl IIlI is inclined as at H5,

while the corresponding endportion of the pawl I02 is provided with a V-shaped notch I I6.

Rotatable on an axis parallel to the center axis of thestem 94, there is a worm screw, III having a pinion I I8 cut on one end thereof and journaled within a hardened bushing H9, which is vcut away as at I 20 for enabling operative engagement of the pinionIB with the gear Hit. The worm screw III is in operative engagement with a worm gear I21 rotatable on an axis perpendicular to the support 25, and having a shank I22 extending through the cover 4'5, on which shank is rigidly secured by a key I23 and cap screw I25 a sprocket wheel I 25 meshing with the chain 33. This sprocket wheel has a sleeved extension I25 journaledwithin a hardened bush- I ing I26. Beside the sprocket wheel I25, there is a chain guiding roller I2! rotatable on a vertical shaft I28, which is carried by the casing 3i and held in position by a-nut I29. j

In the operation of the mechanism, motive fluid from the connection 39 is admitted to the feed regulating valve I8 via the passage 85. When the valve is positioned as shown in Figs. 3 and 9, the passage 85 is closed by the valve, causing the feeding mechanism to remain inopera tiveirrespective of the actuation of the drilling motor 28 which may have motive fluid supplied thereto through the throttle valve 40. If the feed regulating valve is rotated about 45 I in either direction, the groove 84 will register with the passage 85, admitting motive fluid into the longitudinal groove 84 and V-shaped groove 90, from where it is admittedto the annular groove ii? of the valve chamber 55 through theport 93. From the groove 61, the motive fluid will flow into thevalve groove 51 and therefrom to the holding area BI via the port 63, thereby holding the valve in the position shown in Fig. 4, allow- Iing the motive fluid into the upper end of the piston chamber 49 via the, groove and the passage 12. The: motive fluid acting on the piston 5I will drive it downwardly. When theport I4 is uncovered by the piston, motive fluid from the piston chamber 49Wi1l be admitted to the I actuating area 5% for shifting the valve toward the left in Fig. 4, thereby admitting'motive fluid to the lower end of the piston chamber 49 via the valve groove 58, the annulargroove BIl and the passage I3, while the valve is maintained in this new position by motive fluid admitted on the holding area 62 through the port 64. The motive fluid within the lower end of the piston chamber 49 will flow to the end of the stem 52 through the port 54 and passage 53, thus cooperating with the h I action of the fluid on the under side of the piston til for driving the piston upwardly. During this upward stroke the motive fluid previously admitted into the upper end of the piston chamber,

49 will exhaust through the passage I2, the grooves t6, 5? and I55, the passage III, the port I0, and exhaust port ll. the port I5, the motive fluid will flow to the When the piston uncovers actuating area 59 for shifting the valve into the position shown in Fig. 4. In this instanca the motive fluid previously admitted to the holding area 60 will exhaust through the vent I6. As the piston5I is again driven downwardly, the motive fluid previously admitted into the lower end of the piston chamber 49 will exhaust through the passage I3, the grooves 68, 58and 69, the

passage IILthex port l0, and exhaust port II.

groove is of a V-shaped cross-section and of a depth gradually diminishing toward its enduntil it verges with the normal peripheral wall of the valve. 1 Due to the operative engagement of the rack 99 formed on the piston stem 52 with the 2" pinion 98 formed on the longitudinally disposed stem 94, the reciprccatory motion of the piston 5I will impart an oscillatory motion to the stem 94 and tothe pawls Ill! and I02 carried thereby. IfIthe feed regulating valve I8 is positioned so as to cause the registration of its groove 88 (Fig. 12) with the port I I3, the motive fluid from the valve-groove 84 will flow to the actuating area III for shifting and-"maintaining the wedge I08 in the position shown inFig. 5. In this instance,

the valve-groove 86 (Fig. 11) will register with the port H2, aiiording communication of the wedge actuating area IIII with the atmosphere through the passages QI, 81, 82, andthe ports In and I I. In this position of the wedge IE8, its annular bead IM engages the pawl I MI to maintain it in the position shown in Fig. 16, that is out of engagement with the teeth lilt of the ring I05, while thepawl I532 is capable of engage ment with the teeth 'IM due to the. position of the wedge-beadII4 into the notch H6. With the I pawls Hit and I02 thus positioned, the oscillatory movement imparted to the stem 94 will effect a step by step rotary motion of the ring H35 in a clockwise direction in Fig. 16, which rotary motion is transmitted to; its integral gear I05, and

therefrom to the worm screw III due to the operative engagement of its integral pinion H8 with the gear Hit. The worm screw III meshing with the worm gear IZI will transmit intermittent rotary motionthereto in a counterclockwise direction in Fig. 10, causing the rotation of the sprocket wheel I25 in the same direction. This sprocket Wheel meshing with the chain 33 will cause a step by step slidable movement of I the drilling motor 26] relative to the support 25 for feeding the motor to the work.

When it is desired to feed the drilling motor from the work, the feed regulating valve may be positioned for communication of its groove 81 with the port I I2, and its exhaust groove 89 with the port H3. In this instance, the motive fluid I previously admitted on the wedge actuating area I59 will exhaust to the atmosphere through the port IE3, the groove 89 and the passages 92, 8|, 32, and ports III and II. Simultaneously, motive fluid from the longitudinal groove 84 will flow via the groove 81 and the port I I2 to the actuating area III! of the wedge I08 for shifting and maintaining the wedge at the end of its rearward stroke, that is in a position wherein the annular bead H4 thereof engages the inclined end wall H5 of the pawl Illl, allowing this pawl to engagethe teeth I84 of the ring I05, while the pawl M2 is moved inwardly out of engagement with the teeth I 04 by the bead H4 moved out of the notch H6 and engaging the pawl between the notch H6 and the adjacent end of the pawl. With the pawl IOI engaging the teeth HM of the ring [05 and the pawl I02 out of engagement, the

I the power actuated piston 5| results in the feeding motion of the drilling motor 20 in either direction, which motion is transmitted thereto by the worm gear 12! and theworm II! forming a self locking assembly preventing the worm II! to be rotated by the gear l2l. With this self locking rotation transmitting mechanism, it will be apparent that the drilling motor 20 never travels at a greater rate of speed than that resulting from the operation of its feeding mechanism, which has its speed controlled by the valve 18; For instance when drilling vertical holes, the drilling motor 20 is always looked to its support-25 due to the operative engagement of the sprocket wheel I25 with the chain 33, which sprocket wheel has its rotation checked by the self locking mechanismincluding the worm HI and worm gear I21.

Although the foregoing description isnecessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific, terminology is not intended to be restrictive or confining and it is to be further understood that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. The combination with a drilling motor, of

' feeding means for said motor comprising a houscillatory movement of said member for transmitting a step by step feeding motion to said motor including a tooth ring, pawls carried by said vmember operatively engageable with one or the other side of the teeth of said ring for transmitting rotary motion thereto in one or the other direction, and fluid actuated means for selec tively controlling the operative engagement of said pawls with the teeth of said ring.

2. In a drilling apparatus, the combination with a support having a drill slidable thereon,-

ing motion to the drill, pawl means operatively associated with said element and member for transforming the oscillatory movement of the former into a stepby step rotation of the latter in one or the other direction resulting into forward or backward feeding motion of the drill, and fluid actuated means operatively associated with said pawl means for controlling the direction of rotation of said member.

3. In a drilling apparatus, the combination with a support having a drill slidable thereon, of feeding means for the drill comprising a feed motor, means including a toothed member .deriving motion from said motor for transmitting feeding motion to the drill, pawls selectively engageable with the teeth of said member for controlling the direction of said feeding motion, and fluid actuated means operatively associated with said pawls for controlling their engagement with the teeth of said member.

4; In a drilling apparatus, the combination With a support having a drill slidable thereon, of feeding means for the drill including a toothed member rotatable in two directions, means deriving motion from the rotation of said member in one or the other direction for imparting forward or backward feeding motion to the drill including pawls selectively engageable with the teeth of said member, and fluid actuated means operatively associated with said pawls for controlling their engagement with the teeth of said member. 1 Y

5. In a drilling apparatus, the combination with a-support having a drill slidable thereon, of feeding means for the drill including an oscillatory member, a driven element, clutch means between said member and element operable for transmitting rotation to said element selectively in one or the other direction, and fluid actuated means operatively associated with, said clutch means for controlling the operation thereof and the consequential direction of rotation of said element.

ALBERT FEUCHT. 

